Adopt Stackless UI: warm palette, sidebar, project tab bar with Design tab

- Add Google Fonts (Newsreader/Outfit/IBM Plex Mono) + warm beige CSS palette
- New VIBNSidebar: Stackless-style 220px sidebar with project list + user footer
- New ProjectShell: project header with name/status/progress% + tab bar
- Tabs: Atlas → PRD → Design → Build → Deploy → Settings
- New /prd page: section-by-section progress view
- New /build page: locked until PRD complete
- Projects list page: Stackless-style row layout
- Simplify overview page to just render AtlasChat

Made-with: Cursor

app/[workspace]/projects/layout.tsx

@@ -1,9 +1,8 @@
 "use client";
 
-import { WorkspaceLeftRail } from "@/components/layout/workspace-left-rail";
-import { RightPanel } from "@/components/layout/right-panel";
+import { VIBNSidebar } from "@/components/layout/vibn-sidebar";
 import { ProjectAssociationPrompt } from "@/components/project-association-prompt";
-import { ReactNode, useState } from "react";
+import { ReactNode } from "react";
 import { useParams } from "next/navigation";
 import { Toaster } from "sonner";
 
@@ -14,26 +13,16 @@ export default function ProjectsLayout({
 }) {
   const params = useParams();
   const workspace = params.workspace as string;
-  const [activeSection, setActiveSection] = useState<string>("projects");
 
   return (
     <>
-      <div className="flex h-screen w-full overflow-hidden bg-background">
-        {/* Left Rail - Workspace Navigation */}
-        <WorkspaceLeftRail activeSection={activeSection} onSectionChange={setActiveSection} />
-
-        {/* Main Content Area */}
-        <main className="flex-1 flex flex-col overflow-hidden">
+      <div style={{ display: "flex", height: "100vh", background: "#f6f4f0", overflow: "hidden" }}>
+        <VIBNSidebar workspace={workspace} />
+        <main style={{ flex: 1, overflow: "auto" }}>
           {children}
         </main>
-
-        {/* Right Panel - AI Chat */}
-        <RightPanel />
       </div>
-      
-      {/* Project Association Prompt - Detects new workspaces */}
       <ProjectAssociationPrompt workspace={workspace} />
-      
       <Toaster position="top-center" />
     </>
   );